Environmental Rules in Glenn County, CA (2026)
4 rules for unincorporated Glenn County, California.
Verified from official government sources
Stormwater Management
New subdivisions in unincorporated Glenn County must be engineered to withstand a one-hundred-year flood without damaging structures or neighboring property, and stormwater cannot be discharged onto county roads without the public works director's approval, under Code Section 15.65.010. Chapter 15.65 sets the pipe sizes, easement widths and channel standards that carry that requirement into design specifics.
Glenn County Subdivision Drainage Requirements
Some RestrictionsGlenn County Code § 15.65.010
All subdivisions shall be protected from flood hazard and inundation by storm waters originating without and within the proposed subdivision. The design and construction of drainage facilities shall be such that water courses traversing the subdivision and water emanating from within the subdivision will be carried through and off the subdivision without injury to improvements, residential site...
Erosion Control
In unincorporated Glenn County, commercial and industrial development projects must follow eight erosion control performance standards under County Code Section 15.56.060, including minimizing exposed soil, preserving natural features, and installing sediment basins to catch runoff during construction.
Glenn County Erosion Control Standards
Some RestrictionsGlenn County Code § 15.56.060
The following erosion control standards shall apply to all development projects in commercial or industrial zoning districts: The smallest area practical of land shall be exposed at any one time during development; When land is exposed during development, the exposure shall be kept to the shortest practical period of time; Natural features such as trees, groves, natural terrain, waterways and o...
Flood Zones
In unincorporated Glenn County, no one may build, fill, or alter land within a mapped area of special flood hazard without a development permit from the county's flood plain administrator. The county adopted FEMA's 1997 Flood Insurance Study and Flood Insurance Rate Maps to draw those zones, and the Glenn County Building Official issues or denies every permit under Glenn County Code Chapter 15.54.
Glenn County Floodplain Development Permits
Some RestrictionsGlenn County Code § 15.54.070
A development permit shall be obtained before any construction or other development begins within any area of special flood hazard established in Section 15.54.040. Application for a development permit shall be made on forms furnished by the flood plain administrator and may include, but not be limited to: plans in duplicate drawn to scale showing the nature, location, dimensions, and elevation...
Flood Elevation Requirements
In unincorporated Glenn County, new and substantially improved structures built in a special flood hazard area must have their lowest floor elevation certified by a licensed engineer or surveyor and verified by the county building inspector. Glenn County Code Section 15.54.100(D) sets the elevation and floodproofing rules, including a stricter add-on standard for the AO flood zone.
Glenn County Flood Elevation Standards
Some RestrictionsGlenn County Code § 15.54.100(D)(2), (D)(6)
The elevation of the lowest floor, including basement, shall be certified by a registered professional engineer or surveyor, and verified by the community building inspector to be properly elevated. Such certification and verification shall be provided to the flood plain administrator at plan check, prior to vertical construction, and at final inspection. ... New and substantially improves resi...
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